Process for cleaning vehicles



3,457,109 Patented July 22, 1969 3,457,109 PROCESS FOR CLEANING VEHICLES Rolf Peist, Dusseldorf-Holthausen, Germany, assignor to Bohme Chemie, Dusseldorf, Germany, a corporation of Germany No Drawing. Filed Nov. 5, 1965, Ser. No. 506,597 Claims priority, application Gelrmany, Nov. 12, 1964,

Int. Cl. 1368b 3/10 vs. (1134-29 4 Claims ABSTRACT OF THE DISCLOSURE DESCRIPTION OF THE INVENTION This invention relates to a new and improved method for cleaning vehicles. More particularly, this invention relates to a method of cleaning motor vehicles by washing the vehicles with solutions of anion-active or nonionogenic cleaning agents; rinsing with water containing specific surface active agents; and subsequently drying.

Generally, vehicles, and particularly motor vehicles are Washed with soaps or detergents containing anion-active or non-ionogenic cleaning agents and the wash water is removed by an ordinary water rinse. In such a process the rinse water forms a compact water film which adheres strongly to the vehicles surface. The removal of this film is necessary to prevent the formation of visible spots and streaks which are formed by hardening constituents, inorganic salts or other impurities present in the cleaning agent. Heretofore, this water film had been removed by either wiping the vehicle as with chamois leather or by using heat action or blowers. While the prior art methods for removing the water film are effective to a large extent there are attendant therewith certain disadvantages. For example, the wiping method requires a substantial expenditure of manual labor, while the use of heat or a blower requires considerable consumption of energy. In any event, the appearance of visible spots on the surface of the washed vehicle cannot always be prevented.

Accordingly, it is an object of this invention to provide a process for cleaning vehicles that overcomes all of the aforementioned disadvantages of the prior art.

Another object of this invention is to provide a process for cleaning vehicles that substantially eliminates the conventional drying processes of the prior art.

A further object of this invention is to provide a process for cleaning vehicles which eliminates the appearance of visible spots on the surface of the Washed vehicle.

Another object of the invention is to provide a process for cleaning vehicles which is less costly and more efficient than any of the prior art processes heretofore used.

Accordingly, it has been discovered that the aforementioned objects may be accomplished by adding a small amount of cationic surface active agent to the rinse water. By the addition of a cationic surface active agent to the rinse water it has been unexpectedly found the formation of a dense water film on the surface of the vehicle is prevented and the rinse water, not completely removed, remains thereon in the form of droplets or small wet streaks, which, for the most part run off by themselves, as they possess only a slight adherence to the washed surface. Moreover, any few droplets remaining on the surface may be conveniently blown off by merely setting the vehicle in motion thereby rendering any further drying completely superfluous. In any event, by using a rinse water containing small amounts of a cationic-surface active agent it has been found that no visible residual matter remains on the surface, whether the remaining droplets are allowed to fall off or are removed by the aid of a blower.

The surface active compounds added to the rinse water and operable for purposes of this invention are any of the known cationic surfactants. These cationic surfactants include those containing non-quaternary nitrogen, those containing quaternary nitrogen bases, and those containig non-nitrogenous bases. Such surfactants are disclosed in the text Surface Active Agents and Detergents, volume II, pages 103-119 by Schwartz, Perry and Berch.

Those compounds especially suitable for this invention are those containing a quaternary nitrogen group and at least one lipophilic high molecular radical having from 8 to 20 and preferably 12 to 18 carbon atoms.

Some of the more common quaternary ammonium compounds may be represented by the following general formula:

wherein, R is an aliphatic or cycloaliphatic group having from 8 to 20, and preferably from 12 to 18 carbon atoms; a, b and c are members selected from the group consisting of lower alkyl, lower hydroxylated alkyl, phenyl and benzyl; X is a member selected from the group consisting of halogen, methosulfate, ethosulfate, sulfate and bisulfate.

The high molecular radical may be bonded in known manner to the quaternary group through hetero atoms or atom groups such as --O-, COO-, CON-, -N-, and S--.

Examples of compounds represented by the above general formula are: trimethylhexadecyl-ammonium sulfate, diethyl octadecyl phenyl ammonium sulfate, dimethyl dodecyl benzyl ammonium chloride, octadecylaminoethyl-trimethyl-ammonium bisulfate, stearylamido-ethyltrimethyl-ammonium methosulfate, dodecyloxy-methyltrimethyl-ammonium chloride, cocoalkylcarboxyethyl-di- (hydroxyethyl) methyl ammonium methosulfate, the cocoalkyl radical being derived from coconut fatty acid having a chain length distribution of 12 to 18 carbon atoms.

Other quaternary nitrogen surfactants especially effective for purposes of this invention are those containing the basic nitrogen as part of a ring structure and having at least one lipophilic aliphatic or cycloaliphatic group containing from 8 to 20 and preferably from 12 to 18 carbon atoms. Among these compounds quaternarized pyridines, quinolines, tetrahydroquinolines, tetrahydroisoquinolines and their corresponding ring substituted halogen derivatives are well known. Examples of these compounds are dodecyl-pyridinium chloride and hexadecyl-quinolinium phosphate.

Examples of non-quaternary nitrogen surfactants which are also useful for purposes of this invention are the primary, secondary and tertiary amines containing at least one lipophilic aliphatic or cycloaliphatic group having from 8 to 20 and preferably from 12 to 18 carbon atoms. Exemplary of these compounds may be mentioned dodecylamine or the addition product of 2 mols of ethylene oxide with dodecylamine in the form of their water soluble salts.

Other non-quaternary surfactants which may be used are isothiuronium compounds, substituted by an aliphatic or cycloaliphatic group having from 8 to carbon atoms, such as dodecyl-isothiuronium chloride.

In addition to the quaternary nitrogen compounds mentioned the corresponding constituted compounds with the quaternary phosphonium or the ternary sulfonium may also be utilized.

The cationic surface-active compounds are added to the rinse water at a concentration of about 0.01 to 1 gram/ liter and preferably from 0.03 to 0.5 gram/liter. The addition is carried out advantageously with the aid of an automatically operating dosimeter. Generally, the cationic compounds are used in the form of concentrated aqueous solutions, to which solvents such as alcohols, glycols, or other organic water miscible solvents as well as solubility increasing agents may be added to increase the solubility and resistance to low temperatures.

The various mechanical procedures utilized in cleaning vehicles are well known in the art and form no part of this invention. Thus, conventional machines and devices may be utilized. The individual working steps of washing, rinsing and drying may be performed manually or with the aid of equipment operated either partially or entirely automatically. The minimum equipment generally required comprises a primary nozzle spray tunnel for a first rinsing, a washing-brushing tunnel, a final rinsing station and a blower tunnel for drying. The washingbrushing tunnel may, for example, have two-side and one-top brush. As required, additional equipment such as a vacuum cleaner, more brushes and a Wheel washing station may be provided. Furthermore, a manual washing station may be provided between the washing-brushing tunnel and final rinsing station. The primary washing tunnel may also contain spray equipment for washing the bottom of the vehicle.

The anion-active and non-ionogenic cleaning agents are well known in the art. Examples of these are: fatty alcohol sulfates having chain lengths of from 12 to 18 carbon atoms, fatty alcohol-ether sulfates obtained by the sulfatization of the product produced by the addition of 1 to about 4 moles of ethylene oxide to fatty alcohols, alkyl benzene sulfates having alkyl radicals of from 9 to 14 carbon atoms, sulfosuccinic acid ester, fatty alcohol polyglycol ethers with about 4 to 10 oxyethylene groups and alkyl phenyl polyglycol ethers with about 4 to 10 oxyethylene groups. The anionic cleaning agents are generally present in the form of alkali, ammonium or alkanolamine salts. As a rule the cleaning agents are used in the form of their concentrated aqueous solutions. If necessary the aqueous solutions may contain auxiliary solvents, such as alcohols, etc., and other additions such as waxes and the llike. The cleaning agents are generally used in concentrations of about 0.1 to 0.5 'gram/ liter.

The invention may be further described by the following examples which are not to be considered as limitative in any respect.

Example I With the aid of an automatic dosimeter, a aqueous solution of dodecyl-pyridinium chloride was dosed into the rinse water of an automatic car washing plant so that the rinse water contained 0.05 gram/ liter of dodecylpyridinium chloride. The operation consisted of nozzle Washing, then rinsing and finally blower drying. For each vehicle about 30 liters of the rinsing solution was used. It was found that the drying time was shortened by onehalf in comparison to the usual process of rinsing without any addition of a cationic-active agent. Furthermore, in spite of the increased speed in passing through the drying process, the vehicles left the cleaning plant practically completely dry and free of visible spots and streaks.

Example II In the last rinsing process of an automatic car washing plant equipped with a nozzle spray tunnel for a first rinsing, a brush tunnel for washing, a zone for manual washing, a nozzle spray tunnel for final rinsing and having connected thereto a blower tunnel for drying, a final aqueous rinse solution containing 0.06 gram/ liter of dodecylthiuronium chloride was used. The final rinse solution was prepared, with the aid of an automatic dosimeter, by dosing measured quantities of a 10% aqueous solution of dodecylthiuronium chloride into the final rinse water. For each vehicle about 50 liters of liquid for the last rinsing were used. Compared with the usual process, without addition of a cationic agent in the final rinsing water, the drying time was cut in half. In spite of the increased rate of passing through the blower tunnel the vehicles were practically dry, and were free of any spots and streaks.

While specific examples and preferred modes of practice of the invention have been set forth it will be understood that this is solely for the purpose of illustration and that various changes and modifications may be made without departing from the spirit of the disclosure and the scope of the appended claims.

I claim:

1. In a process for cleaning vehicles utilizing a compound selected from the group consisting of anion active and non-ionogenic cleaning agents, including the steps of rinsing and drying, the improvement which comprises:

using an aqueous rinse solution containing a cationic surfactant selected from the group consisting of dodecylpyridinium chloride and dodecylthiuronium chloride, in an amount of about 0.01 to about 1 gram/ liter of said rinse solution.

2. A process according to claim 1 wherein said cationic surfactant is present in a concentration of from 0.03 to 0.5 gram/liter.

3. A process according to claim 1 wherein said cationic surfactant is dodecyl-pyridinium chloride.

4. A process according to claim 1 wherein said cationic surfactant is dodecylthiuronium chloride.

References Cited UNITED STATES PATENTS 2,472,794 6/1949 Cothran 1342 9 XR 2,526,286 10/1950 Schwarzkopf et al. 13423 2,633,437 3/1953 Detjen 134-32 XR 2,671,037 3/1954 Stoddard 134-30 XR 2,677,630 5/1954 Scales 13429 XR 3,050,422 8/ 1962 Zak 134-36 XR 3,142,590 7/ 1964 Hergonson 1347 FOREIGN PATENTS 884,546 12/ 1961 Great Britain.

MORRIS O. WOLK, Primary Examiner J. T. ZATARGA, Assistant Examiner US. 01. X.R. 13442, 36, 37 

